State-of-the-Art Report on : Roundabouts Design, Modeling and Simulation

This research investigated the state-of-the-art in roundabout design and analysis. The research team also investigated the use of a computer based simulation package for the design and analysis of roundabouts in the U.S. The Visual Simulation Environment (VSE) simulation tool was acquired and tested. Numerous traffic factors and standards were found to be important in the simulation model. Three main criteria should be considered: safety, delays, and capacity. These criteria can be used to study the feasibility of using roundabouts, determine optimum design parameters, compare traffic scenarios, or compare a roundabout to an intersection, among other design functions. This research pointed also to the significance of driver behavior. An essential element in the simulation of roundabouts is the gap acceptance process, as gap acceptance at roundabouts is likely to be different from traditional gap and lag times used for acceptance and rejections.